One concern associated with the implantation of a blood pump is the clotting of blood due to the presence of the pump in the blood circulatory stream. Any edge or crack or protrusion, for instance, that contacts the blood flow could serve as a location where blood could collect and clot, or cause disruption of the blood and result in blood clotting.
To minimize the possibility of a blood clot, it is desirable to minimize edges or protrusions present in the blood flow path. One approach to meeting this constraint is to avoid the use of any sensor that would introduce an edge or protrusion in the blood flow path. However, it is also important to know the flow of blood through the pump. It is thus desirable to be able to identify the flow of blood through an implanted pump without the presence of sensors in the blood flow path.
More problematic, the presence of sensors in an implanted pump will increase the need for separate wires, or connections to the sensors, through the patient along which the signal integrity must be reliably maintained. Because the implanted pump and supporting wiring for current to power the pump are already quite intrusive, it is desired to avoid any additional wires having to be present to connect to the pump through the patient. For this reason, it is desired not to need sensors and thus additional associated wires extending from the sensors through the patient.
The present invention provides for the identification of flow through the implanted pump in the heart without the need for any flow sensors. When a bi-ventricular assist is needed, this invention can be used to regulate the pump flow rate on both sides of the heart to ensure balanced device outputs.